Spine deformity最新文献

Study design: This is a retrospective single-center study.

Purpose: The purpose is to investigate the incidence of distal junctional kyphosis (DJK) when fused proximal to the stable sagittal vertebra (SSV) in adolescent idiopathic scoliosis (AIS) patients undergoing selective thoracic fusion.

Methods: We retrospectively reviewed a consecutive cohort of surgically treated AIS patients with Lenke 1-2 A/B curves between 2011 and 2022 with a minimum of 2 years of follow-up. The SSV was defined as the vertebra bisected by the posterior sacral vertical line on long-standing sagittal radiographs. All patients underwent posterior pedicle screw instrumentation, and the decision of fusion level was at the surgeons' discretion. Distal junctional kyphosis was defined as ≥10° angulation between the lower instrumented vertebra (LIV) and the vertebra below the LIV (LIV + 1). Patients were stratified into Fusion proximal of SSV (Prox-SSV) and fusion including SSV (Incl-SSV). Multivariable backward regression was performed to identify predictors for DJK.

Results: A total of 196 patients were included, with 80 in the Prox-SSV group. The overall DJK rate was 3.6% (7/196), occurring in 6.3% (5/80) in the Prox-SSV group and 1.7% (2/116) in the Incl-SSV group, respectively (p = 0.125). Fusion proximal of SSV did not significantly increase DJK risk (Univariate OR 7.98, 95% CI 0.87-66.6; excluded in multivariable regression). Using SSV for LIV selection would extend the fusion by one level in 63.8%, two in 25.0%, and three in 11.2% of patients.

Conclusion: The overall risk of DJK is small in thoracic curves and fusion proximal to the SSV did not significantly increase the risk of DJK. Standardized use of SSV as LIV would result in a substantial extension of the fusion area with questionable benefits to the patients.

Purpose: To date, natural history studies on scoliosis development describe only curve progression but do not include its initiation. Around 50% of children with 22q11.2 Deletion Syndrome (22q11.2DS) develop a scoliosis. Longitudinal data from a large cohort of 22q11.2DS patients is available. This study aims to inventory the natural history of scoliosis development, starting before curve onset, in 22q11.2DS patients.

Methods: 22q11.2DS patients are biennially radiographically screened for scoliosis from age 6 to adulthood. All available radiographs were analyzed. Outcome measures were: skeletal maturity (modified Risser classification), coronal Cobb angles, curve angle fluctuation and treatment (bracing, surgery or no treatment). An evaluation was performed of scoliosis onset, risk of progression to > 30°, curve angle fluctuation and treatment.

Results: 722 full-spine standing radiographs of 292 patients were included. 116 (40%) of the patients developed a curve ≥ 10°, 44% of girls and 36% of boys. Thirteen (4%) progressed to a curve > 30° and seven (2%) required surgical treatment. In patients with radiographs before age 10, 49% already had a scoliosis. 22% of the patients already had a curve ≥ 10° at first visit. More fluctuation compared to a predicted trend line was seen in future scoliosis patients.

Conclusion: It appeared that many 22q11.2DS patients already have fluctuating spinal asymmetry before age 10, often without progression, and that only a subset develops a severe progressive deformity. This longitudinal dataset provides the opportunity for future risk-profiling to distinguish between stable versus progressive scoliosis for the 22q11.2DS population.

Purpose: Proximal junctional kyphosis (PJK) is a condition frequently encountered in children with early onset scoliosis (EOS) undergoing growth-friendly instrumentation (GFI). Previous studies have identified risk factors but have not compared the rate of PJK between children with connective tissue disease (CTD) and idiopathic EOS (iEOS).

Methods: Retrospective review of a multicenter spine database was performed. Patients with EOS undergoing GFI with a minimum of 5 years follow-up were identified and isolated to those with CTD (Marfan, Loeys-Dietz, Ehlers-Danlos, Soto, and Larsen) and idiopathic etiologies. PJK was defined as requiring revision surgery or as having > 10 degree change in proximal junctional angle (PJA). Surgical factors and implant variables were recorded. Radiographic parameters and complication development were compared between groups.

Results: A total of 253 children (mean 5.7 years, 57% female) were identified (CTD:49, iEOS:204). A total of 58 patients developed radiographic PJK (23%) with only 11 (18.9%, 4% of total cohort) undergoing revision surgery at 5 years following implantation. There were no identified surgical factors or radiographic variables associated with the development of PJK. In comparing the CTD and iEOS cohorts, there was no difference in PJK (CTD:26.5%, iEOS:22.1%; P = 0.5). Additionally, there were no significant differences between groups for preoperative or 5-year follow-up radiographic parameters, although there was a trend toward greater increase in PJA from post-implant to 5 years in CTD patients (CTD: 2.5 ± 13.8° vs - 0.01 ± 9.9; P = 0.08). CTD and iEOS patients gained similar thoracic heights, 26.6 ± 20.7 mm vs 26.9 ± 21.7 mm (P = 0.8). There was no difference in overall complication rate but CTD patients experienced a greater number of complications/patient (3.1 vs 2.0; P = 0.004).

Conclusion: PJK is a pervasive complication in EOS, occurring in 23% of patients undergoing GFI. Having an underlying CTD did not increase the risk of PJK development within 5 years of treatment.

Purpose: Implant-related complications can occur after the surgery for adolescent idiopathic scoliosis (AIS) and remain untreated for long periods until they become painful enough for intervention. This can result in a rigid deformity with vertebral fusion and disc degeneration within the scoliotic curve. This report aimed to emphasize the importance of early revision surgery illustrated in three unique cases.

Case description: The cases presented were as follows: a 48-year-old female who had experienced implant failure following posterior corrective fixation left untreated for 25 years; a 32-year-old female who had experienced implant failure following anterior corrective fixation left untreated for 16 years; and a 23-year-old male who had experienced pseudarthrosis following posterior corrective fixation and had been left untreated for 5 years following implant removal. All patients exhibited vertebral fusion and disc degeneration within the exacerbated major thoracolumbar/lumbar scoliotic curve as well as kyphotic deformity because of prolonged neglect after implant failure. In all cases, surgery required an anteroposterior combined procedure with anterior intervertebral release, posterior fusion mass osteotomy, and asymmetric pedicle subtraction osteotomy.

Conclusion: When implant failure occurs after AIS surgery, early surgical intervention can enable less extensive revision with reduced risk before stiffness and fusion of the bone mass develop. Regular long-term follow-up is therefore essential for early detection of implant failure. Moreover, when recommending revision surgery, it is critical to intervene at an appropriate time, ensuring that patients fully understand both the risks and benefits, including the psychological burden of residual deformity.

Purpose: To define anatomical landmarks on the vertebrae at each spinal level for surgeons to use intraoperatively as a guide for the placement of juxtapedicular screws in the setting of hypoplastic or absent pedicles.

Methods: Preoperative computed tomography (CT) of patients with adolescent idiopathic scoliosis (AIS) was analyzed for thoracic pedicles ≤ 3 mm wide, measured between the outer cortices at the isthmus, as these may require a juxtapedicular screw for safe placement. For these pedicles, a simulated juxtapedicular screw was placed into the vertebrae using image reconstruction software. The distance from the screw's insertion point was measured in the axial plane to the medial and lateral borders of the superior articular process (SAP) and to the posterior tip of the transverse process (TP), and in the sagittal plane to the junction of the SAP and TP. Screw trajectory angle was measured between the longitudinal axis of the screw and the sagittal and axial planes.

Results: Of 6324 pedicles, a total of 378 pedicles (6.0%) met inclusion. The average distance to the medial and lateral borders of the SAP was 14.7 ± 3.4 mm and 10.7 ± 5.4 mm, respectively; to the tip of the TP was 9.0 ± 3.9 mm, and to the TP/SAP junction 2.8 ± 1.6 mm. The average angle in the axial plane was 21.1 ± 4.4° and in the sagittal plane it was - 4.2 ± 3.6°.

Conclusions: Preoperative CT scans were used to map a safe starting point and trajectory for juxtapedicular screw placement in thoracic vertebrae. These findings can assist surgeons with thoracic pedicle screw placement.

Purpose: Magnetic controlled growing rods (MCGRs) are used to treat early-onset scoliosis when nonsurgical options fail, controlling curve progression and allowing for continued spinal growth. Recent reports of unplanned reoperations and mechanical failure of MCGRs have led to further research. This is a systematic review on the retrieval analysis of explanted MCGR rods. Understanding the failure mechanisms will shed light on the survivorship and complications associated with the implant.

Methods: A Medline and EMBASE database search was performed, looking at all variations in the terms "magnetic controlled growing rods" and the terms "retrieval/explant/metallosis" All published retrieval analysis studies of MCGR were included, and all clinical outcome studies, biomechanical testing studies, review articles, and case reports were excluded. Data were collected regarding the source, year, and aim of the study; number of patients and rods analysed; duration of implantation; and main findings and conclusions.

Results: Nine studies (454 rods) reported metallosis due to O-ring damage (67%), internal mechanism failure of locking pins (45%) and rod fracture (7%) in all MCGR generations. Actuator locking pin fractures reported in 174 rods (38.3%) continue to persist despite newer implant iterations. The pin fracture rates decreased from 52% in MAGEC 1.3 to 15% in MAGEC X.

Conclusions: MCGR failure is multifactorial, and metallosis is of significant concern because of the unknown long-term effects in patients. Early recognition and revision of existing rods in situ is essential, along with continued efforts to reduce mechanical failure in future iterations of MAGEC.

Levels of evidence: MCGR failure is multifactorial, and metallosis is of significant concern because of the unknown long-term effects in patients. Early recognition and revision of existing rods in situ is essential, along with continued efforts to reduce mechanical failure in future iterations of MAGEC. This systematic review provides Level III evidence on failure mechanisms in MCGR, as the results were obtained from Level III studies. The levels of evidence for all relevant references can be found in the reference section.

Level ii: [1-4].

Level iii: [5-34].

Level iv: [35-44].

Level v: [45-50].

Purpose: To biomechanically compare screw strains above and below a vertebral column resection (VCR) during segmental compression (SC) and cantilever bending (CB) performed via traditional methods and a novel, construct-to-construct accessory rod ("rail") technique.

Methods: Eight cadaveric torsos underwent a VCR with 25⁰ kyphosis at T8 with pedicle screws implanted three levels above and below the VCR (T5-7; T9-11). Four screws (T6, T7, T9, T10) were instrumented with strain gauges to capture screw strains during SC and CB. Both deformity corrective maneuvers were performed over a traditional construct (central rod) and over a construct-to-construct accessory ("rail") rod. Real-time screw strains were collected and peak strains were compared between corrective techniques.

Results: Strains in screws closest to the VCR were significantly less during "rail" compression compared to traditional SC (T7: p = 0.015). Maximum screw strains were significantly lower during "rail" SC and CB compared to traditional SC (T6: p = 0.037; T7: p = 0.015) and CB (T6: p = 0.018; T9: p < 0.001). Total screw strain was more evenly distributed over all screws during "rail" compression and CB compared to traditional techniques, which concentrated strain at individual screws adjacent to the VCR.

Conclusions: Performing segmental compression and cantilever bending across a lateral accessory construct-to-construct ("rail") rod resulted in significantly lower strain on individual pedicle screws adjacent to a thoracic VCR compared to traditional SC and CB. As such, the "rail" may lessen risk of screw pull-out and screw plough during maneuvers to correct spinal deformities across a VCR.

Purpose: The purpose of this single centre radiographic study on healthy volunteers was to evaluate three novel orbito-cervical parameters in a population of healthy volunteers and calculate the observer agreements and errors for these parameters.

Methods: The cohort comprised 126 healthy adult volunteers, 88 females and 38 males, aged 33.6 ± 12.0, with full-spine sagittal radiographs and no history of back and/or neck pain, spine and/or lower limb pathologies, or spine and/or hip surgeries. The following were measured on radiographs: C1-slope (C1S), orbito-cervical tilt (OCT), orbito-cervical incidence (OCI), chin-brow vertical angle (CBVA), McGregor's slope (McGS), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). Pearson's correlation coefficients were calculated between all radiographic measurements.

Results: C1S was 9.8 ± 6.6°(range, 0.1-29.1), OCT was 66.7 ± 6.9°(range, 48.7-82.0), and OCI was 75.9 ± 7.2°(range, 52.5-89.8). All measurements had excellent observer agreements (ICC > 0.900) and low observer errors (MAE < 2.5). OCI strongly correlated with C1S + OCT (r = 0.95, p < 0.001). OCT strongly correlated with McGregor's slope (r = - 0.78, p < 0.001), moderately correlated with CBVA (r = 0.64, p < 0.001), but weakly correlated with OCI (r = 0.46, p < 0.001). C1S moderately correlated with OCT (r = - 0.51, p < 0.001), OCI (r = 0.5, p < 0.001), CBVA (r = - 0.52, p < 0.001), and McGregor's slope (r = 0.64, p < 0.001).

Conclusion: OCI is strongly correlated with C1S + OCT and these orbito-cervical parameters are to some extent correlated with existing sagittal cervical parameters. Furthermore, they have excellent observer agreements (ICC > 0.900) and low inter- and intra- observer errors (MAE < 2.5). The authors recommend the use of these orbito-cervical parameters in clinical practice to provide a better understanding of horizontal gaze, leading to improved preoperative planning for spinal fusion.

Purpose: To present a case where the novel Modern Luque Trolley (MLT) technique was used to manage a patient with early onset scoliosis (EOS) and to assess the outcomes including graduation to fusion.

Methods: Case report.

Results: A 5-year-old female with EOS associated with Prader-Willi syndrome underwent T5-L4 MLT surgery in April 2015. The operation, post-operative course, and 9-year follow-up period were uncomplicated. No autofusion occurred throughout the 7-year growth phase. In April 2022, the patient underwent elective uncomplicated "graduation" surgery to remove the MLT and posterior T5-L4 instrumented fusion was performed. Thirty-one months post-graduation, no complications occurred. During the 7-year growth phase, pre-index, immediate post-index, and 7-year post-index radiographs were analyzed. Scoliosis decreased from 52° to 10° post-index and then increased at 7 years to 31°. Maximal kyphosis increased from 24° to 27° post-index to 43^o at 7 years. T1-T12 coronal height increased from 16.0 cm post-index to 20.7 cm at 7 years. T1-S1 coronal height increased from 25.9 cm post-index to 33.9 cm at 7 years. T1-T12 sagittal spine length (SSL) was 15.6 cm post-index and then increased to 20.4 cm at 7 years. T1-S1 SSL increased from 27.2 cm post-index to 35.8 cm 7 years. T1-T12 3D true spine length (3D-TSL) increased from 16.2 cm post-index to 21.5 cm 7 years and T1-S1 3D-TSL increased from 27.3 cm post-index to 36.4 cm 7 years.

Conclusion: These findings demonstrate the potential of MLT to decrease spine deformity and permit spinal growth while reducing autofusion.